In coastal and non-coastal areas subjected to high winds and flying objects from wind and rain storms, tornadoes, hurricanes or typhoons, accordion shutters traditionally have been used that lacked the strength to resist flying objects like a 9 pound 2.times.4 traveling at 34 M.P.H. while resisting hurricane force winds in excess of 155 M.P.H. on an 8 feet tall shutter, installed on a one story residence. Some accordion shutters are much larger in blade width, and component thickness, while actually being weaker. Others are very heavy and bulky causing considerable difficulty in operation, have large protrusions from the wall when stacked and difficulty walking over the wide bottom track when used across doorways and are extremely expensive and unattractive. Further, as a plurality of separate systems must be connected when covering larger areas due to installation and transportation difficulties of large single systems, prior accordion systems required that locking pins be provided and custom holes drilled in the header and sill extrusions to provide for adequate strength in the connecting areas. Also, accordion shutters have historically required two or three guide pins per blade, with one or two rows of these guide pins following the outside of a top and bottom guide track while others ride in a groove.
When leaving the accordion shutters in an open position, there has heretofore been no convenient method of securing the contracted shutters in the open position. By providing a securing clip an effortless securing means has been provided for. This invention addresses the shortcomings of previous accordion shutters by providing resistance to high winds and protection from a 9 pound 2.times.4 traveling at 34 M.P.H. Further, it has a very low weight per square foot of deployed shutter system and is easy to operate. It has minimal protrusion from the wall when stacked at edges of the opening and the system provides for ease of maintenance for the guide pins, trolley and blade replacement and the capability of the accordion shutter to be assembled from factory assembled smaller sections, in the field, by the unique gate locking system hereinafter described. This facilitates the installation of very wide shutters without undue weight problems for the installer.
The present invention provides an improved header and sill design which allows for less damage to the shutter blade on impact. By providing a header and sill which include one or more vertical elongated protrusions which are in contact with the shutter blade itself, the positive impact of the wind is absorbed by the shutter blade instead of the pin. The shutter blade can naturally withstand greater force than the pin. While older versions of the present invention could not pass multiple impacts from large-missile impact tests, the improvement to the header and sill of the accordion shutter system of the present invention now allow it to pass such tests.